Electromagnetic driving system



p 50 1. o. RUUD 2,521,653

ELECTROMAGNETIC DRIVING SYSTEM Filed Dec. 29, 1947 Patented Sept. 5, 1950 UNITED STATES PATENT oFFicEi v ELECTROMAGNETIC DRIVING SYSTEM" Ivar Qiaus Build, Oslo, Norway Application'Dccemb'el 29, 19.4.7; Scrial'No. 194,349" In: Sweden March 23,1946."

The present: invention relates to an electrom netic driving system especially-for hair cut tingmachines, safety razors or the like; and which is so shaped that it may be mounted within the handle of such apparatus.

Electra-magnetic driving. systems. areknown in which. a swinging lever-is disposed as the iron core in a coil adapted; to be connected to a source of alternating: current and mounted. axially; in. the

handleof the apparatusv and has one and capable of oscillating between the poles of a permanent magnet also mounted; axially in. said handle, wherebythe lever has a reciprocating motion im- .parted to 'it in accordance withthe frequency of the alternating current employed. Further, it is known, to arrange the, iron core of'thecoilstationary and the permanent magnet attached: to-

The. prcsentinvention, has for its object to momma (01.172-126) provide an electro-magnetic system of the type v referred to which has great.- effect and: which in =use w-ill not; become heated to' a perceptible degree; even. if it is connected ,directly'to a normal source ofalternating current;

The invention consists-mainly in'thatboth the electromagnet. and the permanent magnet are :provided with a number-of operative poles.

In one embodiment of the invention the multi poled magnets are'disposed' in alignment with the pole faces facing each other; one of said magnets being supported swingable and provided with a projection serving as an actuating arml Ina further embodiment both of the, multipoledmagnets are stationary havin between 'their'cooperating pole {aces anumberoi movable actuating piecessecured in spaced relation at. the end of a. common swinging lever ofr. onmagnetic materialim uch a manner thateach of said actuating pieces is magnetized inaccordance with t adj c nt pole'of the elcctromagnet.

In the accompanying drawing: a. constructional .form f a. h r cutt n machineaccording-tactile invention is illustrated by wayof example.)

Figure 1 shows a plan view of the machine with the upper half of the handle removed? andisome detailsin section,

Figure 2. a longitudinal section at rightangles to Figure-1',

Figure. 3- a cross. section alongthe lineIII -III in-Figure2, V

Figure 4a plan view or a modified, embodiment ofthe' invention, and

Figure 5 a cross section along the line: li V in Figure 2..

In the drawing l denotes a permanent magnet having a central north pole and asurrounding sleeve-shaped south pole, and 2 denotes anelectromagnet having an .U- shaped iron core with a coil 3'. Y

The magnets: .l and 2 aredisposed with the pole: faces facing'each other, axially in a handle consisting" of two halves 4. and" 5; and at opposite sidesof' the central poleof the magnet l, which has a square or rectangular cross section; are disposed levers 6 of nonmagnetic material; Said levers ,6 extend in the longitudinal direction of the magnet. I' from aga-p'l betweenthe pole faces of the magnets l andiz and through slots it inthe magnet I to somewhat in; front. oi" the bottom thereof. The last: mentioned ends-.- are firmly in 'terconnected' by a distance piece 9 having a headshaped end portion 10?; The assembled arms and distance piece; are mounted on a pivot stud i3 supported in angle pieces l2 of a ring-shaped member I: l secured at thebottom of the: magnet I. Thus the arms: form a two-armed2 swinging lever p'ivotable on studs t3;

The pole facesof theimagnets If and: 2, which are facing: each other, coincide with cylindrical f-aces having their axis in the pivot axis of the swinging lever.

Between the ends of the arms fiextellding into the gap. 1; which ends are somewhat: enlarged in the breadth direction, are secured two actuating pieces. I14; of magnetic materiah Said pieces M, having: a. cross section adapted inaccordance with the curvature of the-gap I, are secured" at such a. distance from each other, that each of them at the position of rest, is positioned before the. middle. of" a gap between the poles of the permanent: magnetv l, and has such} a; length; counted inthe direction of motion, that said gap always. being covered said piece during the motion thereof. The magnets I and 2 may be interconnect/Edict means. of: a sleeve-shaped connecting mcmher: it of. nonmagnetic-Katmai; and; for; preventing: Cone tactbetween thevswingingglcver andsaidimember 1:5, rubber buffers- '62 are-with advantageiprovided enlargement 25 serving as handle by means er said permanent magnet; and a pole piece arranged in the ga and means for mounting said pole piece in movable relation to said electromagnet and said permanent magnet; said pole piece having a length sufiicient to cover the gap between said poles of said permanent magnet.

2. An electromagnetic driving system comprising in combination a swinging lever; an electrop 7a permanen magnet having three poles and "means'assbia'ted with a said lever and cooperating with said magnets for which the member 23 may be -.rotated about its i axis in order to bring two contact pieces 26 (Figure connected to the terminals of leads noma source of alternating current into and oiit from contact with said springs 2l,whereby"the ciir-Y rent to the coil 3 may be closed or interrupted;

respectively.

When the current to .the coil 3, by turning the switch member 23, is closed :themagnet; Z-isJenergized and the poles thereof changegtheirapo- 'larity r in accordance with the frequency; of: the alternating current employed. At the same'time .each of the actuating pieces I4. becomes'ma'ghetized in accordance with the'adjacent pole ofithe electromagnet 2, anddue to the influence thereof and of the permanent magnet l a reciprocating motion being imparted torthe pieces! 4. and :thus alsogto the swinginglever in time to the fre q y I), 3 I

By the useof movable actuatingpieces both of the magnets I and 2 may be stationary without any decrease in 'theeffect-of the -apparatus; as

the pieces lit-mayberegardeddike additional poles which: are secured --to..the swinging lever and which by the energization in accordance with the adjacent.- stationaryv poles ofthewmagne-tcfl, cooperate with the permanent magnet? 12in a similar manner as if the magnet 2 hadbeen sup-- ported swingable. In addition,. theembodiment described has; the advantage 'of-" constituting an assembled unity whichoccupies a small'room and can-be housed-ina convenient handle.

Instead of the uselof actuating-piecesi-M one'of K5 the magnets'c'an be supported swingab-leas shown in Figure 4.- The permanent magnet 2'l is"sta'- tionary and provided with-ta central pole'and'a surrounding sleeve-shaped south pole thel'sa'me manner as the magnet l.-. Theelectromagne't 29, having an U-shaped iron core, is swingable on a tap25 and provided withia promotional-serving as-an actuating arm. The pole faces of the respective magnets coincide with cylindrical faces having their axis in the pivot axisof the;electr0:-

magnet 28. The middle of each pole faceeof fthe magnet-28 is'placed before the middlebf-a gap between the poles of the permanent'imagnet" 2.1 and the pole faces have such a. length in: the 'di:- rection. of motion that theyin all positions-of motion-cover'said gaps. -rr When thecoils 3| of the electromagnet; 28ia're connected to a source of alternating currenttlie magnet. 28 will reciprocate in accordance'with the frequency of the current, asabove' described. As will be understood the' per'manent magnet may be supported swingabie andtthe electromag net stationary. "'lclaimt" 1. In an electromagnetic driving system-y iii combination, an electromagne't having adjacent poles; apermanent magnet'havingfadjacent poles, said magnets being arranged with said poles. in juxtaposition so as to :leave a gap: betweenisaid poles of said electromagnet and said poleswof imparting a reciprocating motion to said swinging IQVQlfg'iQ accordance with the frequency of an alternating current flowing in said electroina'gnet'.

3.Anelectromagnetic driving system comprising in;:.combination a swinging lever; an electromagnet having two poles; a permanent magnet havin g three adjacent poles and means associated with said lever and cooperating with said magnets for imparting'a reciprocatingmotion to s'aid swinging lever in, accordancetzwith' the frequency of analtern'a'ting current flowingin'saidelectro magnet.- I o T- 4. In an electromagnetic:drivingisysteni; an combination; a permanent. magnet"having three poles-arrangeddn' E formgthe outer two -of' 'said poles having like polarity opposite to that of-the middle one of said polesy a =U-shap'edelectr'o magnet having two" poles, said magn'ets ilbein'g disposed in alignment with said .po'les' faci'ng' each other; a 'movable me'mber arranged between the poles of said-permanent magnet and saidz'electromagnet; and means for-mounting said member, said meanscooperating withsaid magnets to im; partf'a reciprocating motion to said membermfir --5:'In' an electromagnetic :idriving". systemwin combination, a permanent magnet having i'thre'e poles arranged-intE-iorin, :the outer two tofasfaid poles having liketpolarity opposite :t'o'that 'ot-vthe middle'o'n'e of" said poles; a U-shaped electromag net having" two "poles, sammagnets' :bein'g 'dis' iposed in alignment with said poles :facing'f'each other 'and defining: ai'gap; iand= a ieve'r s'wihgably mounted: and having pole pieces inith'e "gap, said magnets beingadapted to i. part inmooperation a reciprocating" motion "to' sai'd swingingslever in accordance with .the 'fre'quency of an alternating .currentfiowing in said 'electr'omag'netr '6. In 'anelectromagnetic driving system, in combinationpa permanent magnet having three poles arranged in E-f'orm, th'e' outer-twoof said poles having like polarity 'oppositeto that 'ofthe middle one of said 'poles;-*a u sliaped electro magnet having two poles} said 'm'a'gnetsweing disposed'in alignment withisaid' pole's'facing each other and-defining a gap-between said magnets; and-;a swingable leverof non-magnetic; material;

aplurality of pole ,pieces ing-said: gap connected to the endgoflsaid swingingleveneach of said pole pieces at the. position .orrestbeing .placed bei ore the middlelof a I gapfbetween the poles of aid. Perman n masn t 'n h vinga, lengbh d lir said" per poles arranged in E-form; and a U-shaped electromagnet having two poles, said magnets being disposed with said poles facing eachother, one of said magnets being swingable in relation to the other of said magnets and having a projec- 5 tion fordriving a tool, each of the poles of said electromagnet having the middle of its face placed before a gap between the poles of said permanent magnet and having a length sufficient to cover the gap in all positions of relative motion between said magnets.

10. A driving system as claimed in claim 9, said poles of said magnets having faces being parts of cylinders having their axes coinciding with the ivotal axis of said swingable'magnet.

' IVAR OLAUS RUUD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 10 Number Name Date 1,743,478 Pratt Jan. 14, 1930 1,995,449 Edwards Mar. 26, 1935 

